A passive optical network (PON) comprises a central terminal, the optical line termination (OLT), which serves a plurality of optical network units (ONUs) at or near subscriber locations. PONs are described more fully in ITU-T G.984.3, titled “Gigabit-capable Passive Optical Networks (G-PON): Transmission Convergence Layer Specification” (March 2008) and ITU-T G.987.3, titled “10-Gigabit-Capable Passive Optical Networks (XG-PON): Transmission Convergence (TC) Specifications” (October 2010), in IEEE 802.3ah (2004), “Media Access Control Parameters, Physical Layers, and Management Parameters for Subscriber Access Networks,” and in IEEE 802.3av (2009), “Physical Layer Specifications and Management Parameters for 10 Gb/s Passive Optical Networks.” In a power-splitting PON, the OLT launches a modulated signal into an optical fiber. The signal is divided by a tree of optical splitting devices, or in some cases electrical repeaters, such that each ONU receives a copy of the complete signal, from which it decodes a subset of the signal that is of interest to itself.
In the upstream direction, each ONU transmits its traffic in a series of distinct bursts, each of which is orchestrated by the OLT in such a way that bursts from separate ONUs do not overlap in time; time-interleaved resource sharing is often referred to as time division multiple access (TDMA). The signals from the plurality of ONUs are merged by the tree of passive optical splitters to reach the OLT by way of a single fiber.
In traditional copper pair communications, there is a direct relationship between a physical pair of wires at the central office and a given subscriber terminal However a PON is a multiple-access medium, and there is no physical way to uniquely associate a given subscriber with a given terminal, for example on the OLT.
To deliver the correct service to a given subscriber, it is necessary to assign a physical ONU device to the subscriber, and to associate some identification of that physical ONU device with the protocol layers of the service. Frequently, an ONU identification is the factory serial number burned into the ONU when it is manufactured, but it can be any information whose uniqueness can be assured within the scope of the operator's domain, e.g., a media access control (MAC) address. The ONU identification information may be permanent, as in the case of a serial number or MAC address, or alterable, as in some of the cases described further below.
The process of associating an ONU with a subscriber begins when the subscriber contacts the telecommunications operator's service order entry (SOE) function to place an order for telecommunications service. The SOE function collects subscriber information such as name, street address, desired set of telecommunications services (for example: Internet service tier or IPTV channel line-up), and any pre-existing information that may need to be carried over, for example, a pre-existing telephone number, or possibly even a complete service definition. The latter could be appropriate in the case that the subscriber is moving from one home to another.
The SOE function supplies service definition information to a provisioning operations system (POS) function, which is responsible for translating the subscriber's street address into a specific central office, a specific multi-PON OLT terminating equipment (in the case of interest for this invention), and a specific PON. The POS also interprets information such as IPTV, internet or telephone service parameters into the necessary detailed bit and byte-level provisioning information necessary to configure the OLT, the ONU, and possibly other elements that are not pertinent to this invention (for example authentication parameters in an authentication server).
Possibly through the mediation of an element management system (EMS) function, the POS communicates the OLT and ONU parameters to the proper OLT. Because no ONU has yet been installed, the OLT retains these parameters, pending the appearance and registration of the proper ONU. The OLT is then said to have a pre-provisioned service for the given subscriber. The EMS assigns a subscriber management identifier (SMI) to the subscriber's ONU. This is normally a sequence of fields in the nature of                <OLT identifier>-<slot number>-<port number>-<ONU number>,where the first three fields are fixed by the network and equipment topology that serves the subscriber's particular location, and the ONU number is free to be chosen at will, as long as it does not conflict with another SMI. Customarily, the ONU number is selected as an integer in the range from 1 to the maximum number of ONUs supported on the particular PON, for example 64. The SMI uniquely identifies the subscriber, and all of the subscriber's provisioned services, in a way that can be sent to the correct OLT, where it comprises most of the information necessary to deliver service to the subscriber from the previously provisioned service parameters, namely a slot and port number. In the context of this invention, the SMI is not necessarily the same as the later described subscriber identification used to identify a specific subscriber out of all of the telecommunication operator's customers, although it will be apparent to one of ordinary skill in the art that the SMI may be used in some embodiments as the subscriber identification.        
When the OLT discovers a new ONU, the OLT assigns a PON address to the ONU, that is, a value through which the ONU is identified in PON transactions across the optical distribution network. The OLT assigns a PON address to a specific ONU, which it identifies by the ONU's serial number. The discovery protocol of all PON systems includes a method in which the ONU reports its serial number to the OLT. In the present description, the term ONU identification is used to include any single information element or combination of information elements that are permanently associated with a particular ONU during manufacture and that are, individually or in combination, unique to that ONU. In this sense, a MAC address, for example, is logically the equivalent of an ONU identification; or in another case the ONU identification may include, or consist solely of, the ONU's serial number.
However, no service can be delivered until a correlation or a mapping is established between the subscriber's identity, subscriber identification (e.g., SMI), and the specific ONU that is installed at the subscriber's premises. This is logically equivalent to the necessity for the SMI to be correlated to the ONU's PON address. The process of associating a service and billing entity (the subscriber) with a physical ONU, and associating the physical ONU with protocol layer identifiers, is called registration.
The SOE system also coordinates the service order with a work force administration (WFA) function, to assign a work order or installation order to a particular installer, possibly at a particular date and time. The work order contains information about the street address, the required ONU type, and service information such as a telephone number or IPTV subscription profiles, such that the installer is capable of verifying service at the time of installation. It is to be noted that, in this use case, no specific ONU identifier is included in the work order. The installer is free to use any available ONU of the proper type.
It will be appreciated that most of the information items noted above, as well as a work order number, can be used to uniquely identify the subscriber, the intended geographic location of the ONU, and the specified services. Accordingly, the term subscriber identification is to be understood to encompass any of these or other information items that are uniquely associated with the collection enumerated above. Knowing the subscriber identification is also equivalent to knowing the SMI in the OLT system.
It is desirable to pre-provision service into the telecommunications network, and particularly into the OLT, such that, when the ONU is physically installed at the subscriber premises, service comes up immediately, and the installer can verify the integrity of all services while still on-site, and therefore without the need for the delay and expense of an additional site visit.
In one registration solution, a service provider selects a particular ONU from inventory, assigns that ONU's identification to a subscriber installation order (i.e., subscriber work order), and assures the correct ONU is installed at the subscriber location. This registration solution is referred to herein as the pre-registration solution and is, at least partially, described in ITU-T G.984.3 Amendment 1, titled “Gigabit-capable Passive Optical Networks (G PON): Transmission convergence layer specification; Amendment 1—Specification of the ONU registration method and various clarifications” (February, 2009). This solution is further described in Broadband Forum Technical Report TR-156, titled “Using GPON Access in the Context of TR-101” (issued December, 2008). Since the ONU identification and subscriber identification are known a priori, it is straightforward for the service provider to associate the ONU identification with the subscriber identification and provision telecommunication service to the ONU via the SMI into the OLT serving that ONU. With this method, the OLT and ONU are able to initialize service as soon as the ONU is installed in the PON for on the spot service validation.
However, the pre-registration solution presents significant logistical problems. Specific ONUs must be identified in inventory, located in a warehouse, and moved from the warehouse to a staging area to a truck to a subscriber's premises by multiple personnel over the course of at least a few days. There are many opportunities for errors in this sequence, and, absent errors, there is always the possibility that the designated ONU turns out to be damaged or defective and, therefore, cannot be used.
The pre-registration solution may be suitable for some ONU installations, for example, PON-fed remote multiplexes or multiple-dwelling units (MDUs). Such installations are characterized by having been planned under engineering work orders, rather than subscriber installation or repair work orders. The lower volume of these installations may make it feasible to stage specific ONU equipment. However, the pre-registration solution is not ideal for high-volume residential ONU installation.
Another registration solution, referred to herein as the pre-provision solution, does not presuppose that ONU identification is known in advance of ONU installation. Service is pre-provisioned for the subscriber using the subscriber identification at the OLT but without a corresponding ONU identification. At installation time, an installer selects any ONU of the proper type from those ONUs available, for example on the truck. To associate the ONU with the subscriber, the installer communicates with an operator at the service provider operations center (e.g., network operations center). The installer communicates with the operator through voice or textual communication, for example by way of a cell phone, and supplies the operator with subscriber or work order identification and ONU identification. The operator enters the information into the service provider's back-office service management information technology (IT) system to create an association between the ONU and the subscriber (i.e., register the ONU). The ONU identification is thus correlated with the subscriber identification and the pre-provisioned service parameters. By transmitting the ONU identification to the OLT in conjunction with the pre-provisioned service identifier, the IT system enables the OLT to then bring up service, which can be validated by the installer at the subscriber premises.
The pre-provision solution requires human interaction at both the subscriber premises and the network operations center. Coordination between the installer and the operator may be hampered by the availability of the operator, schedule conflicts, or by any number of reasons that inhibit the operator's ability to communicate with the installer or respond to the registration request. Furthermore, verbal or text-message communication of the subscriber identification and ONU identification is error prone and time consuming. For these reasons, the pre-provision solution is not used in practice.
FIG. 1 is a block diagram illustrating the components of a pre-provision solution according to the prior art. The telecommunications network 100 includes OLT 120 coupled to a plurality of ONUs, of which an ONU 110 newly installed at, or near, a subscriber premises is shown. The ONU 110 is coupled to the OLT 120 via a PON link 121. The OLT 120 is further coupled to a service provider's IT system 170 through one or more network links 171.
During installation, an installer 140 couples the ONU 110 to the PON, performs any pre-service tasks (e.g., mounting the ONU, connecting computers or service devices to the ONU and providing power to the ONU) and then contacts an operator at the network operations center (NOC) 160 via a cell phone 150 through a communication link 151. When the ONU 110 powers up and initializes, it announces itself to the OLT 120 via the PON. Although the ONU 110 supplies its serial number to the OLT 120 as an intrinsic part of the ONU discovery process, the OLT 120 has no way to associate the ONU 110 with a subscriber or with service parameters.
Thus, the installer 140 collects the corresponding subscriber identification and ONU identification. For example, a paper record of a work order may contain the subscriber identification. The subscriber identification may indeed be implicit in the work order number, as is the intended geographic location of the installation. The installer 140 can read the serial number from the housing of the ONU 110. The installer 140 relays this information to the NOC operator via the cell phone 150. The NOC operator creates an association between the subscriber identification and the ONU identification in the IT system 170. The IT system 170 communicates the association to the OLT 120, which provisions telecommunication service to the ONU 110 using the pre-provisioned service parameters.
A third registration solution exists, referred to herein as the registration ID solution. In this solution, the OLT initially associates a new ONU, not by its ONU identification but rather by a registration ID (sometimes also referred to as a password). The registration ID solution is, at least partially, described in ITU-T G.984.3 Amendment 1 and further described in a Telcordia Presentation, titled “ITU PON—Past, Present, and Future” (prepared Jul. 30, 2008). The registration ID solution is further described in Broadband Forum Technical Report TR-156. Upon creation of the installation order or repair order, a registration ID is generated and associated with the work order. Depending on the service provider policies, the registration ID may be very simple (e.g., the ONU number on the PON) or very elaborate (e.g., a cryptographically unique string similar to a license key for commercial software). Telecommunication service is then provisioned with the OLT in association with the registration ID. The registration ID is communicated either to the installer (e.g., via a field on a work order) or to the subscriber (e.g., by postal mail). Upon installing the ONU, a registration ID prompt is presented (e.g., by a simple web page served by the ONU) and the registration ID is entered into the ONU or into a computer connected to the ONU. It will be appreciated that serving a web page by the ONU increases the cost and complexity of the ONU to a degree and exposes the underlying software to potential tampering.
When the ONU initializes onto the PON with the OLT, the OLT associates the ONU to the proper SMI by its registration ID only. During this initialization, the OLT also learns the ONU's identification. Once the OLT learns the ONU identification, the OLT may be instructed to switch from registration ID recognition to ONU identification recognition, such that the registration ID is no longer used. This process is commonly known as locking the ONU.
Although the registration ID solution is widely used, it has its own disadvantages. One of these is apparent in the fact that a locking policy may be required: if the subscriber has actual or potential access to the registration ID, it can be changed, affecting either service or security, or both. It is also inconvenient and error-prone to enter an especially long registration ID, and there is no standard feedback mechanism by which the OLT can convey an error message and an invitation to try again.
The pre-provision solution would be the preferred method of registration if it were possible to avoid the coordination and communication problems inherent between humans. Therefore, the present disclosure describes methods, systems, and apparatus to overcome the disadvantages described with reference to the pre-provision solution.
It will be appreciated that, if an existing ONU fails and must be replaced, the identity of the new ONU must be discovered in one of the same ways that have been described above for new ONU installation.